Risers are used in offshore drilling and production to connect a surface platform to subsea equipment of a well. Drilling risers are used during drilling operations. Production risers are normally used to convey production fluids from the subsea well to the platform. One type of a production riser comprises pipes having threaded ends that connect together.
The length of a production riser may be thousands of feet, and the diameter can be fairly large. As the riser string is being made up and run into the sea, a new pipe or joint being added to the upper end of the riser string will be rotated to make up the threads. Rotating the new joint while avoiding cross-threading can be difficult.
In U.S. Pat. No. 9,145,745, the new joint is added without requiring rotation. A collar with internal threads is rotated relative to both the box and the pin. The box has deflectable fingers with internal grooves that mesh with external grooves on the pin as the collar rotates. A collet ring is located between the fingers and the collar, and has external threads that engage the internal threads of the collar. By requiring a collet ring, the connector of U.S. Pat. No. 9,145,745 has more elements over other types of connectors.